X-ray tube



E. WANDNER.

X-RAY TUBE.' APPLlcArma-e FILED JULY 21, m9.

1,359,300- Emma Nw, 52

UNITED STATES PATENT OFFICE.

EDMUND WANDNER. OF CHICAGO, ILLINOIS.

X-RAY TUBE.

Application'led July 21, 1919. Serial No. 312,194.

Chicago, in the county of Cook and State ofI Illinois, have inventedcertain new and useful- Improvements in X-Ray Tubes; and l 'do declarethe following to'be a full, clear,

and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

This invention relates to X-ray tubes, and it relates more specificallyto an improved heating unit and associated regulator.

One object of this invention is to provide an improved X-ray deviceincluding a man'- ually controlled regulator by means of which a verysteady or uniform vacuum can be maintained in the X-ray tube, and bymeans of which the vacuum can be lowered so as to prevent the tube-frombeing punctured, and from being distorted to such eX- tent as to destroyor impair the focus of the tube. c

Another object is to provide an improved device of this character whichaffords the operator an easy and direct control of the current and alsoprovides a fine range whereby he can obtain a steady vacuum in the tube.

Another object is to provide for effectually regulating the electriccurrent strength and thereby generating a greater or less quantity ofmetallic gases within the tube, according to varyingT circumstances.

Another object is to eiiciently heat the vacuum tube, vby the employmentof a low tension current such as derived from an ordinary electric lampsocket.-

Another object is to provide for regulating the vacuum. withoutdisconnecting the current, by simply varying the current.

Another object is to provide a device ofl this character which isextremely durable and thoroughly practical.

Other objects and advantages may become apparent to persons who read thefollowing details of description) in connection with the accompanyingdrawings, in which:

Figure 1 is aside elevation of my improved vacuum tube in connectionwith the lead for connecting it to'an external source or current ofelectricity.

Fig. 2 is an enlarged detail view, partly in longitudinal section.

Fig. 3 is a perspective view ef the heating coil and its adj uncts.

Referring to these drawings in detail, in which similar referencecharacters correspond with similar parts throughout the several views,the vacuum tube comprises a transparent bulb 5 having diametricallyopposite extensions (3 and 7 which contain the usual anode S and cathode.9, respectively, and the vacuum tube also comprises a hollow extension10 which is formed integrally with the bulb 5 and with a tubular element11 suclras illustrated Ain detail in Fig. 2. The parts 5, 6, 7, 10 and11 are preferably formed integrally of glass, and are, therefore, bothtransparent and insulating.

Referring now particularly to Fig.v 2, it will be seen that a screw-plug12, adapted t0 fit an ordinary electric lamp socket, receives the outerendA of the tubular element 11 where it merges with the outer end of theextension 10; and this plug 12 is also adapted to lit a regulator orrheostat-socket such as illustrated at'13 in Fig. 1, this socket beingprovided with a regulating handle 14 whereby the resistance and currentstrength may be regulated in the well known manner.

A"conducting wire is connected with the hollow elements 10, 11 and 12 inthe following mannert'A. wire of relatively high resistance has itsmajor portion coiled about the inner end of the tubular element 11 asindicated at 15,-a sheet of mica 16 being preferably disposed betweenthe tubular element. 11 and the coil 15. The ends of this wire connectwith terminal wires 17 and 18 at points indicated at 19, and anintermediate portion of this high resistance wire extends through anaperture 20,'thence toward the inner end of the tubular element and outthrough a notch 21 formed in the inner end of the said tubular element.This tubular element 11 is Aformed with a partition 22'at its middleportion, so that air or gas can 'pass therethrough, and at the oppositeside of this partition from the aperture 20, the tube is provided withtwo apertures 23 through which the terminals 17 and 18 extend from theexterior` at 19, to the interior at 23, and these terminals connectrespectively to the metallic shell of the screw-plug 12 and to the usualcontact element 24, as indicated in Fig. 2.

It is understood, of course, that the inner end portions of theterminals 17 and 18 cornpletely fill and seal the apertures-:23.4Although I have found it convenient to connect the high-resistance orheating wireto the terminals 17 and 18 as indicated in Fig.' 2, it isnot beyond the scope of this invention to dispense with the joints 19and extend the high-resistance wire into the screw-plug 12 in lieu ofthe terminals 17 and 1S.

Referring now to Fig. 3, it will be seen that the high-resistance wire15, after passing outward through the notch 2l, is interlocked with thelower or inner turn of the coil as indicated at 25, and although thisshort-circuits the lower turn to a certain extent, it is advantageous inthat it secures the coil in a deiinite and fixed relation to the tubularelement 11. It is to be understood, of course, that any appropriatenumber of turns may be employed in the heating coil, and that the turnsof the coil may be insulated from one another in any appropriate way.

Referring again to Fig. 1, it will be seen that the lower on inner endof the heating unit, shown in Fig. 2, terminates approximately at thecentral portion of the bulb 5, that is, approximately at the path ofcurrent between the anode and cathode 8 and 9, and therefore, thismetallic resistance coil not only generates heat within the bulb 5, soas to regulate the vacuum, but it also generates the metallic gas whichconstitutes the conducting medium between the anode and cathode.Moreover, it will be seen that the regulator 13 is directly connected tothe heating unit, and is located in the most convenient position foreasy and effective control by the operator.

Although I have shown the element 1`6 disposed in contact with thetubular element 11, it is within the scope of this invention to disposea metallic sheet or tubular element between the mica 16 and the adjacentpart of the tubular element 11 so that the heating of such metallicelement by the coil 15 would increase the generation of metallic gas,and this increase of the metallic gas can be predetermined by thethickness of the sheet of metal within the coil 15.

Although I have described this embodiment of my invention veryspecifically, itis to be understood that my invention is not limited tothese exact details of construction and arrangement of parts, but I amentitled to make changes within the scope of the inventive ideadisclosed in the foregoing description and following claims.

What I claim as my invention is:

1. In an X-ray device, the combination of an anode, a cathode, atransparent bulb provided with tubular extensions through which saidanode and cathode coperate, a combined heater and regulator comprising atubular element extending into said bulb at a point spaced from saidtubular extensions, a manually controllable current-regulating means onthe outer end of said tubular element, terminal wires electricallyconnected to said current regulating means and extending thence towardthe opposite end of the tubular element, and a heating coil around thesaid opposite end of said tubular element and being electricallyconnected to said terminals.

2. In an X-,ray tube, the combination of an anode and a cathode, and anelectric heating unit spaced from .said anode and cathode and extendingfrom the exterior of the tube to its interior and having its outer endterminating in an ordinary screw plug to lit in and electrically connectwith a lamp socket, the inner end of tlfe heating unit terminatingadjacent to the center of the space bctween the anode and cathode.

In an X-ray tube, the combination of an anode, a cathode, a transparentbulb provided with tubular extensions through which the anode andcathode cooperate, a tubular element formed integrally with andextending from the exterior approximately to the center ot theinteriorof the bulb, this tubular element being spaced from said tubularextensions, a heating and gas generating coil of wire encircling theinner end of said tubular element and supported by the latter, andconducting terminals extendin through the outer part of said tubularelement and electrically connectible with aV source of electric current.

'41. In an X-ray tube, the combination ot an anode, a cathode, atransparent bulb provided with tubular extensions through which theanode and cathode cooperate, a tubular element extending from theexterior lto the 'interior of the bulb and being internally sealed tomaintain the .vacuum in the bulb, this tubular element being spaced fromsaid tubular extensions and having its inner end approximately at thecenter of said bulb, a heating and gas generating coil around andsupportedby the inner tubular element, conducting terminals extendingfrom the exterior to the interior of the tube and connecting with saidcoil, and a hollow' electric connector fitted on the outer end of saidtubular element and having said terminals electrically connected theretoin insulated relation to one another and thereby adapted to beelectrically -connected to a correspondin connector of an externalsource of electricity.

5. In an X-ray tube comprising a transparent bulb, a tubular insulatingelement extending from the exterior to the interior of the bulb andhaving an air-sealing partition in its intermediatc part and an aperturebetween the partition and the inner end of the tubular elf-ment, saidinner end end portion of said Wires extending from the exterior to theinterior of said tubular element at points outwardly beyond thepartition and thence ein tendingr outward through said tubular eiementso that their .outer ends may he eonnected with Mexternal electricconductors, and a heating wire having its ends connected 'respectivelyto the inner ends of said terminal Wires, the major part of said heatingWire being coiled about the portion of the tubuiar member inward of itspartition, a lninor part of the heating wire extending into the.

tubular element through said aperture and thence inward through Saidtube to and through said notch.

G. The combination of a tubular eieinent having apartition intermediateof its ends and having apertures therein at one side of the partitionand an aperture at the opposite side of the partition. and a notch inthe end at the said opposite side, and conducting Wire comprising 'avcoil around said. tubuiar element and a portion extending throufrh saidnotch and through the interior and t e l last said aperture of Saidtubuiar eiement, said Wire also comprising terminaie which. extendthrough the first said apertures and thence through' the interior ofsaid tubular element toward the end opposite the end containing saidnotch` In testimony whereof I`- have hereunto set my hand.

EDMUND WANDNEQ,

